SignStream™ is a MacOS application that provides a single computing environment within which to view, annotate, analyze, and search through video and/or audio data, making it useful for linguistic research on signed languages and the gestural component of spoken languages. SignStream is distributed on a non-profit basis to educators, students, and researchers, and the features in the current release, version 2.0, are described in this article. Program design and development are ongoing, however, and the developers welcome feedback and suggestions.